Preparation of diolefinic resins



c'. 3% 1945. H. L. GE'RHART 2,387,895

PREPARATION OF DIOLEFINIC RESINS Filed DSC. 3, 1943 COPOL YMEI? OUT D/C YCLO PEN THD/ENE 0R Ou. /N apeNT/vD/ENE /N' DI OLE FIN "STOHG'E p Myx/Ek 'n' 0 Q '/5/ 2f 25 r//y/l l 33 l Pff/45H75@ Pen CTO@ .SEP/wen 7 0/6 62 YCEF/DE cofoz. rfv/Ev? Ou T /N f5/v TOF How/912D L GERH/QRT @y MWF@ y excess volatile reactants Patented st.. 326, i945 ii N i assises 2,387,895 PREPARATION OF DIGLEFINIC RESINS Howard lL. Gerhart, Milwaukee, Wis., assignor to Pittsburgh Plate Glass Company, Allegheny County, Pa., a corporation of Pennsylvania Application December 3, 1943, Serial No. 512,769

A(Cl. 26o-23) claims.

The present invention relates to the polymerization of unsaturated hydrocarbons to form resindus bodies and it has particular relation to methods of and apparatus for effecting such polymerization under simultaneous application of heat and pressure.

One object of the invention is to provide a process of anapparatus for polymerizing diene hydrocarbons as a continuous operation.

.A second object is to provide a. process in which are recovered and recycled.

A third object. is to provide a process in which the polymerizationv can lbe quickly and accurately terminated at precisely the right point after a desired degree of resinification has been reached.

A fourth object is to provide a, process in which the amount of reactants undergoing heat treatment at any particular time is small that the hazards of uncontrolled reaction or of explosions are minimized or eliminated.

A fifth object is to provide a process of preparing a. resinous body involving the .use of a relatively dii'licultly polymerizable dicyclopentadiene or cyclopentadiene polymers containing 3 to 5 05H6 units as a starting ingredient.

These and other objects of' the invention will be apparent from consideration of the following specication and the appended claims.

It has heretofore been proposed to prepare polymeric resinous bodies by subjecting a cyclic diolen, such as cyclopentadiene to catalytic addition of molecules. 'I'he products were powdery, relatively insoluble and exhibited a strong capacity for absorbing atmospheric oxygen when exposed to the latter. These polymers, because of these characteristics, have not, heretofore, been satisfactoryfor actual comercial usage.

Conventional methods'of preparing the polyl mers involvebatch operations which, if employed on a large scale, necessitate the treatment of large amounts of materials in closed containers. 'Under naterial had cooled below the reaction temperaure.

It will of course be apparent that with large volumes of highly combustible materials suchas cyclopentadiene the explosion hazards are also quite considerable. The common source of the cyclopentadiene is from dicyclopentadiene from which it is obtained by cracking. This of course is expensive, and also entails considerable loss of material.

In accordance with the provisions of the present invention it is proposed to obviate the foregoing dimculties by subjecting dicyclopentadiene alone or in admixture with'other materials, such as drying oils, lndene, coumarone, to elevated temperature and pressure to form polymers of exceptional value.

As a -further feature the invention contemplates the provision of an apparatus for polymerizing dicyclopentadiene or the like, in which the reactants are caused to iiow as a continuous stream through a reaction zone where they are causedquickly to react and are then removed.

For a better understanding of the invention referencemay now be had to the accompanying drawing in which Figs. 1 and 2 are diagrammatical views illustrating suitable embodiments of apparatus for use in -the practice of the invention.

In the drawing like numerals refer to like parts throughout.

The form of the invention as shown in Fig. 1 comprises a column or tower l0 formed of stainless steel, or other strong, chemically non-reactive, material so fabricated as to be capable of withstanding substantial pressures, e. g., pressures Within a range of about to 120 pounds or more per square inch. 'I'he column is provided with suitable heating means, such as a heating coil Il by means of which the reactants in it may be brought to an appropriate temperature in operation, i. e., about 600 to 700 F. At these temperatures polymerization catalysts are not required. In the reaction there may be employed a polymerlzable cyclic diolefln, i. e., cyclopentadiene or preferably dicyclopentadiene, or other lower P015'- mer such as tricyclopentadiene, tetracyclopentadiene or pentacyclopentadiene containing from 3 to 5 05H6 units per molecule. 'I'he recovery of the latter as a result of partial polymerization of dicyclopentadiene contained in an impure fraction of drip oil such as Dripolene, coal tar or the like is disclosed in an application Serial No. 512,770, filed of even date, and entitled Purifying dicyclopentadlene, by Howard L. Gerhart and Leon M. Adams. These are fed into the column l adjacent to the bottom thereof through a suitable inlet conduit I2. It may be polymerized alone, or it may be conjointly polymerized with an equimolar ratio of a glyceride oil or an ethylenic compound, such as indene. coumarone, methyl methacrylate, styrene maleic anhydride, or the like. In the latter case, the added material, e. g.. a glyceride oil, such as linseed oil. soya bean oil, tung oil, whale oil, perilla oil or other oil preferably of a drying or semi-drying nature is fed into the column through a conduit I3 and flows upwardly conjointly with and in thorough admixture with the hydrocarbon introduced through the inlet i2. 'I'he ratio of oil to hydrocarbon may be approximately equi-molar, but may be substantially. less; e. g. 25 percent molar. A two or three hundred percent excess of oil is also possible. The rate of flow is so adjusted that at the temperature of operation the ingredients will have approximately reached the desired degree of polymerization by the time they have traversed the reaction zone within the column. At the telnperature of reaction a positive pressure of about 60 to 120 pounds per square inch will exist Within the column;

The copolymer resin, approximately at a. satis factory stage of resinificatio'n, is drawn oi at the top of thereaction zone through a conduit I6, which is provided with a valve I5, by means of which the degree of pressure and rate of flow of liquids may be adjusted within the column. The resinous product may be cooled as it is drawn ofi by means of suitable apparatus (not shown) within a period of time so short as substantially to inhibit further polymerization outside of the column. An excess of cyclopentadiene or dicyclopentadiene in the reaction zone may be desired.

, and this excess may be permitted to escape as a vapor or gas at the surface of the polymerized liquid and can then be drawn of! through a conduit i5, having a regulatory valve i1. The vapors are chilled and may be condensed in a suitable cooler coil iB. The recovered diolen can be recycled or, if preferred, can be applied to other purposes.

The resin at least while hot is liquid. It may be cooled and admixed with additional drying oils, thinners, pigments and the like to obtain a paint of desired viscosity and color. It may, also, be further cooked or heat treated in order to obtain a desired degree of bodying.

It will be apparent that the apparatus as herein described is of simple nature' and is susceptible of continuous operations in such manner as to obtain large production with relatively small amounts of apparatus. The resultant resins are relatively soluble in paint and varnish solvents. They also are compatible with other` resins and may be admixed with the latter in large amounts to provide short oil compositions capable of combining with pigments as coloring matter to provide excellent paint and varnishes. Where dicyclopentadiene is employed as a source of cyclic diene hydrocarbon the necessity of subjecting the latter to a cracking operation is avoided. It will be apparent that the dicyclopentadiene may be employed in substantially pure form. A commercial distillate fraction containing percent or more of other hydrocarbons, which either undergo polymerization or else are permitted to escape as vapors from the reaction zone, may, also, be used.

In the form of the invention illustrated. in Figure 2 a reactor I9 may comprise an outer shell 2i, conduits 20 for e. heating medium, such as an inert, relatively, non-volatile oil, mercury or the like. The reactants are carried through the heater shell in a tubular coil 22, which may be oi inert material, such as stainless steel or the like. The charge is introduced into the coil 22 from a mixer 23, having inlets 24 and 26 respectively for the glyceride oil component and the dioleiln component. The glyceride oil may be preheated, almost to the reaction temperature, before itis introduced into the mixer, in a coil 21, which is disposed within a heater jacket 28 having an inlet 29 and an outlet 3l for heating medium.

The time and temperature of heating in reactor coil 22 will depend upon:

1. The nature of the charge.

2. The time and temperature of preheating.

3. The viscosity of the oil.

Where the glyceride oil in the charge is a highly reactive oil, such as tung oil, the rate of reaction with the dioleiin is relatively faster than where the oil is less reactive, such as soya oil. Long preheating has the effect of increasing the viscosity of the charge and greatly shortens the length of time required in the reactor. typical charge such as 60 parts alkali rened embodied linseed oil and parts dicyclopentadiene, the conditions for the reaction without preheating are about 3 hours at 27o-290 C. at a pressure which gradually decreases from 100 to 25 lbs. per sq. inch. When the charge is preheated for 2 hours at 200 C. the reaction time is reducedln half.

' may function as a cooler for polymer, preheater for reactants, and, also, as a separator for unpolymerized diolen. To this end, it is connected by conduit 38 t0 the reactor coil 22 to receive thefreshly formed polymer. Preferably the discharge extremity of the conduit 3B is so constricted as to assure a substantial difference of pressure between the interior of the column 31 and the coil 22.

The glyceride oil contained in storage in tank il is carried by conduit 42, .having pump 42a. to the lower extremity of coil 43, which is contained within the column 31 and is there warmed by heat from the freshly formed polymer, and in so doing cools the latter. The warm glyceride oil is conducted by line 44 to the preheater for further heating. The copolymer resin is ciisY charged from the bottom of the column 31 through conduit 46 while any unreacted, gaseous components escape upwardly as bubbles and are conveyed over through conduit 48, which, as shown in the drawing, discharges into the mixture 23. If preferred, unreacted gases may also be drawn offat the top of the column through conduit 49.

In the drawing is shown a branch 50 for hydrocarbons, upon the conduit 26, which branch lmay optionally be connected by conduits indicated by broken lines at any preselected point to the coil 22. Possible points of connection are indicated at 5i. Similarly optional feed conduits Using a may be connected from oil container Il to the coils by means of conduits indicated as broken lines at 53. In this manner it is possible to feed cool reactants into the reactor at any point in such manner as to admit of exact control of the temperature of the reacting ingredients.

The reactants i'low through the reaction zone as a continuous stream, the total volume of which, at any one time, is small. Fire hazards are thus reduced. It is, also, assured that each portion of the reactants is subjectedl to the desired conditions. The reaction is initiated and stopped at a predetermined point, so that highly uniform products are obtained. If it should be desired to adjust or change conditions in the system, this can be accomplished with a minimum time lag bei'ore equilibrium of the system is reached.

The charge can be varied over wide limits. The copolymer which is most useful as a varnish type product will contain from 30 to 70% oil and 40 to 30% polycyclopentadiene. copolymers which contain less than 30% oil are inclined to he brittle and are of the nature of varnish type gums. copolymers lwhich contain greater than 70% oil are very exible and tend to be of the nature or' synthetic oils. A useful copolymer as prepared from 90% linseed oil, 10%V dicyclopentadiene by this process dries rapidly and may be considered to be a synthetic substitute for China-wood oil for many applications.

The following compositions are illustrative of the charges which can be used:

Example I The copolymer from this composition is a synthetic oil which dries as rapidly as alkali rei'lned linseed oil.

Example Vl Parts Tung nil Linseed nil 3 Dicyclopentadiene 1 Example VII Part Tung nil 1 Dicyclopentadiene 1 The temperature `oi reaction should be above 200 C. and below that of charring or decomposition of the reactants of the product. A range of about 230 to 450 C. may be employed dependent upon the time permissible in the tube. The higher the rate of feed the higher may be the temperature. The time in the reactor tube may be controlled with exactness, merely by varying the rate of feed. The rate of feed for any given apparatus and under any given conditions can be determined by measurement of the viscosity of the product. For most purposes, a product of a viscosity of about E on .the Gardner-Holdt scale is satisfactory, when the finished resin is dissolved in petroleum naphtha Ito give a. 50% solution by weight.

'I'his invention is not to be limited by any explanation of the process by which copolymerization takes place. It is assumed that reaction takes place between monomeric cyclopentadiene and the unsaturated valences in the glyceride oils. Since dicyclopentadien decomposes on treating at about C. into cyclopentadiene it is immaterial whether the charge in mixer A contains the monomer or the dimer' of cyclopentadiene. In a copendingapplication it is demonstrated that the charge may also contain trimer, tetramer or even higher polymeric forms of cyclopentadiene. A charge of this nature is also contemplated for the continuous process. Essentially the salme conditions of operation apply whether the dioleiln in the charge be monomer, dimer, trimer or tetramer.

Example Vm tillation range 97 C. to 190 C. at 4 mm. pressure. 320 parts of this mixture and 480 parts alkali rened linseed oil was fed continuously through the reactor tube. The temperature was within a range of about 275 to 450 C.

The advantage in using the relatively puried trimer and tetramer is that the color of the copolymer is lighter. The glyceride oil copolymers so prepared are equal in every respect to copolymers prepared from dicyclopentadiene and it is intended that methods and products described in copending applications using dicyclopentadiene shall be equivalent when the trimertetramer-pentamer mixture is used in place of the dimer.

It is possible that some cyclopentadiene may react with the olenic diluting impurities under the conditions by which the slush is formed. If such reaction products accumulate in the solid phase of lthe slush and are charged with oil toprepare the copolymer no harm will result., In

fact, many such secondary reaction products are useful in the preparation of these copolymers as described in my copending application Serial No. 470,093, led December 24, 1942, and entitled Modified cyclopentadiene-glyceride copolymers.

A charge containing relatively large amounts of tung oil requires less time and lower temperatures than a charge containing soya or linseed oils. When the ratio of tung oil to dicyclo is greater than 1 to 1, there is danger of forming an insoluble gel. 'I'his danger is not as apparent when there is present some oil such as linseed or soya oil in which case the ratio of tung oil to dicyclo may be raised at will. Oils may be raw, bodied, blown, rened, dehydrated, etc.; in general, all natural or treated glycerides are useful. Oil acids or partially hydrolyzed oils are also useful. The reaction time must be predetermined and is governed by the rate of bodying of the oil and the body desired in the finished resin.

The continuous process has the advantage of e one-step process and produces a resin having good light stability, toughness, light color on' baking, and short drying time. The resins are soluble in th'e common cheaper hydrocarbon thinners, are well adapted as varnishes or as enamel vehicles, and can be applied in the same manner as existing varnishes. They are responsive to the addition oi' driers in the same manner as a varnish.

Useful pigmented compositions are made as shownAby the following examples:

Resin composition ghegill pigggfom' A iaoo cc. tung ou. snr-.msg calcium base.

500 co. bodied soyal oil. Titanium oxido. 1000 cc. dicyclopentadiene.

(These two enamels dry to glive tough white coatings having good Y lig t stability.)

i000 cc. tung oil 300 cc. linseed oil 1000 cc. dicyclopentadione B 2.6 hr./250 0..-. l pai: antimony l o e.

l part Titanox C.

pirt carbon This gray enamel can be used for both airdrying and baking types of finishes. 'I'he use of these resins is not limited to any particular type of pigment. The resins can be used as vehicles for. aluminum, zinc containing pigments, gilsonite, lithopone, etc. Driers may be added either to the charge and be processed with the resin or may be incorporated with the finished vehicle or enamel paste. Certain metallic soaps such' as cobalt, nickel, zinc or copper naphthenates, or the salts of the acids derived from natural glvcerides are useful as addenda to the charge to increase the .body of the resin. 'Ihese salts then act as driers when the mms are subjected to drying conditions.

When pure dicyclopentadiene is the only hydrocarbon in the charge, the resin will usually be a semi-plastic mass which must be thinned for use. This is preferably done while the resin is hot. Any hydrocarbon thinner is useful for this purpose. The charge may contain diluting materials which are normally present in commercial dicyclopentadiene such as indene and coumarone, which are useful modifying agents for resins of this class. The most useful resins areM formed, however, when at least 50 per cent of th'e hydrocarbon charge contains dicyclopentadiene. Other non-resinii'ying diluents are permissible or these may be added during any stage of the resiniflcation reaction to reduce the viscosity.

The use of h'eat and pressure polymerization, as herein disclosed, obviates the necessity of employing catalysts and of course the necessity of neutralizing or eliminating the catalyst residue is avoided. The reaction is moderate in rate and is not excessively Iexothermic, so that it can be controlled with comparative ease and with but little nre hazard. Escape of disagreeably odorous hydrocarbon vapors is also avoided,

The polymerization can be conducted upon senses crude fractions oi' the hydrocarbon component, because under heat and pressure even some of the impurities react and need not be removed i'rom the final product.

Enamels can be prepared from the resins herein disclosed, which have good drying rates even under air drying conditions, and the products are staple, hard, clear and of excellent gloss. They are 'also relatively tree from a tendency to wrinkle.

The forms ot the invention h'erein described are to be considered merely as exemplary. It will be apparent to those skilled in the art that numerous modifications may be' made therein without departure from the spirit o! the invention or the scope of the appended claims.

The present case is a continuation in part of my copending application, Serial No. 324,392, filed March 16. 1940, and entitled Resinous material.

What I claim is:

1. A process of vpreparing a synth'etic resin which comprises continuously nowing a mixture of dicyclopentadiene and an unsaturated glyceride oil under a pressure of about 60 to 120 pounds per square inch through a zone heated to a range of approximately 200 to 450 C. until a conjoint polymerization product in liquid state is obtained and simultaneously continuously withdrawing the polymerization product.

2. A process of preparing a synthetic resin which comprises continuously flowing a mixture oi' a diene hydrocarbon consisting of from l to 5 cyclic CsHs units per molecule and an unsaturated glyceride oil at a pressure of approximately from 60 to 120 pounds per square inch continuously through a tube heated to obtain a temperature oi' approximately 200 to 450 C. until a, liquid conjoint polymer is obtained.

3. A process of preparing a resin which comprises substantially continuously flowing under pressure a, cyclic diene hydrocarbon of the formula (Csi-Is): where a: is a whole number from one to ilve in admixture with an unsaturated glyceride oil through an elongated tube heated to a temperature oi.' about 600I to 700 F. to effect conjoint polymerization of the hydrocarbon and the oil.

4. A process of preparing a synthetic resiny which comprises continuously flowing a mixture of dicyclopentadiene, and an unsaturated glyceride oil under pressure of not substantially less than 60 lbs. per square inch through a zone where it is heated t0 a temperature of approximately 450 C. until a liquid conjoint polymer is obtained.

HOWARD L. GERHART. 

